Definition of decompression in English:

noun

An aviation expert added that even a small explosion on board could have been enough to cause decompression and suck people out of the aircraft.

The plane descended but the reason for decompression could not be found, so the aircraft returned to Oxford.

This seems like the suggestion of a second-rate Hollywood director, for the single reason that you cannot discharge a firearm in a pressurised environment, because there would be catastrophic decompression.